/Engine/Plugins/Runtime/GeometryProcessing/Source/DynamicMesh/Public/Operations/MeshPlaneCut.h
Compute the plane cut by splitting mesh edges that cross the cut plane, but not deleting triangles on positive side.
true if operation succeeds
virtual bool CutWithoutDelete ( bool bSplitVerticesAtPlane, float OffsetSeparatedPortion, [TDynamicMeshScalarTriangleAttribute](API\Runtime\GeometryCore\DynamicMesh\TDynamicMeshScalarTriangleAttrib-)< int > * TriLabels, int NewLabelStartID, bool bAddBoundariesFirstHalf, bool bAddBoundariesSecondHalf )